Basic use of Button in Android

1. Text size and color

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="15dp"
    android:orientation="vertical"
    tools:context=".ButtonActivity">

    <Button
        android:id="@+id/btn_1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button"
        android:textSize="25sp"
        android:textColor="@color/teal_200"
        android:background="@color/black"/>

</LinearLayout>

The background color to take effect: changes themes.xmlFile night to see the situation changes.

Theme.MaterialComponents.DayNight.DarkActionBar.Bridge

2. Customize the background shape

The content of the file is:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <solid android:color="@color/orange_low" />

    <corners android:radius="15dp" />

</shape>

    <Button
        android:id="@+id/btn_2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button"
        android:textSize="25sp"
        android:textColor="@color/red"
        android:layout_margin="15dp"
        android:background="@drawable/bg_btn2"/>

Stroke

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <stroke
        android:width="1dp"
        android:color="@color/red" />

    <corners android:radius="15dp" />

</shape>

3. Customize the pressing effect

Create a drawable file

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:state_pressed="true">
        <shape android:shape="rectangle">
            <corners android:radius="15dp" />
            <solid android:color="@color/yellow_blew" />
        </shape>
    </item>

    <item android:state_pressed="false">
        <shape android:shape="rectangle">
            <corners android:radius="10dp" />
            <solid android:color="@color/blue" />
        </shape>
    </item>

</selector>

    <Button
        android:id="@+id/btn_4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button"
        android:textSize="25sp"
        android:textColor="@color/white"
        android:layout_margin="15dp"
        android:background="@drawable/bg_btn4"/>

4. Click event

Add an attribute, showToast is the method name.

android:onClick="showToast"

Create a function in the corresponding Activity.

public void showToast(View view) {
    
    
    // 提示信息 Toast.LENGTH_SHORT 短时间, Toast.LENGTH_LONG 长时间
    Toast.makeText(this, "一个点击事件", Toast.LENGTH_SHORT).show();
}

The click event is not a Button but can also be set.